Improvement in derricks



WILLIAM M. HOWLAND & GEORGE L. HOWLAND.

Improvement in Derricks. No, 119,612, Patented Oct. 3 ,1871.

UNITED STATES PATENT QFFICE.

WILLIAllI M. HOWLAND AND GEORGE L. HOWLAND, OF TOPSHAM, MAINE.

lMPROVEMENT lN DERRICKS.

Specification forming part of Letters Patent No. 119,612, dated October3, 1871.

To all whom it may concern:

Be it known that we, WILLIAM M. HOWLAND and GEORGE L. HOWLAND, ofTopsham, in the county of Sagadahoc and State of Maine, have invented anew and Improved Derrick; and we do hereby declare that the following isafnll, clear, and exact description thereof, which will enable othersskilled in the art to make and use the same, reference being had to theaccompanying drawing forming part of this specification.

Our invention relates to improvements in den ricks and it consists in acombination, with a chain-wheel which engages the links of the chain soas to draw it without winding around said wheel, ofa chain-keeper orguide adapted to prevent the chain from twisting at the under side ofthe chain when returning to the wheel in letting down the chain afterbeing raised up. The invention also consists in novel arrangements ofapparatus for connecting the shores or braces of the derrick to flatrailroad cars. It also consists in a novel arrangement of reversing-gearfor letting out the chain after raising a load; and it also consists ina novel arrangement of a pair of shore-braces and a connecting-bar,whereby they are connected'together and to the derrick, and may bedisconnected and folded together for transportation.

Figure 1 is a side elevation of our improved derrick mounted on a flatcar. Fig. 2 is a section through the chain-wheel and keeper or guide.Fig. 3 is a front elevation of the derrick. Fig. 4 is a. section of thedevices for securing the shores or braces to the car, the section beingtaken on the line am of Fig. 5. Fig. 5 is a section of the same devicestaken on the line y y of Fig. 4. Fig. 6 is a plan of the upper end of apair of shores or braces and a plate or bar by which they are connectedto gether and to the top of the derrick.

Similar letters of reference indicate corresp 0nding parts.

A and B are the post and arm, such as are ordinarily used for derricks;and O is the hoistingchain. This chain is worked by a chain-wheel, 1),between two ratchet-wheels, E, pawl-levers F, pawls G, connecting-rodsI, and the pawl-lever K, all of which are similar in construction andarrangement to the apparatus described in the patent granted to us the12th day of October, 1869, No. 95,691. We now propose to provide achainkeeper or guide, L, under the chain-wheel, with the chain passingthrough it, to have the links guided so that it will not be twisted whenit passes onto the wheo in lettin g it back after raising a load. Thesaid keeper or guide is provided with four grooves in the wall of thehole, suited to receive the links of the chain as it is being raisedfrom the space below, and turn them, if twisted, to the right positionto be presented to the wheel properly for the points Mto receive eachalternate link between them. Withoutthis guide the chain is liable tocome up to the wheel so twisted that the links will not engage properlywith the wheel.

In this apparatus the chain is let out by the re versing of the actionof the pawls G on the ratchetwheels-that is to say, by causing the pawlsto lift from said ratchet-wheels when the levers F are lifted up and todrop into the notches when the said levers are in the lowermost positionbut the arrangement of devices for efiecting the said actionis quitedifferent from that in the aforesaid patent, the said arrangement beingas follows: The pawls have long rods a connected to them near the loweror free ends by the cranked or bent arms I), which are rigidly connectedto them. Said rods to hang downward obliquely from the front of the postA and pass through an eye, (I, in the outer end of a spring, 6, one foreach, projecting outward from a plate, f, arranged to slide up and downon the post, the ends of the said rods being bent at g to engage thesprings and be pulled downward or prevented from rising by them, whenthe levers F and the pawls ar rive at the uppermost part of theirmovement,

when the reverse motion of the ratchet-wheels is to be effected to letout the chain, the plate fbeing at this time down to its lowest positionon the post to cause the rods a to pull the pawls out at this time; butthey let said pawls drop into the notches when the levers F are in thelowest position, so that by the same movements of the levers F that areemployed for turnin g the ratchetwheels forward, they are allowed toturn backward by the pulling of the chain upon them or the chain-wheel.When the wheels are to be worked forward the plate f is shifted upward,so that the springs and rods to do not act upon said pawls at this time.Two levers, K, are employed for working the pawls, being detaohablyconnected to the metal sockets N for readily shifting to use long orshort levers, as demanded by the nature of the case. They are secured inthe said sockets by a spring, 0, suitably arranged on each The rodsIwhich are to be shifted from one hole, I), to another, according to theweight to be lifted, are secured in said holes by the rod i, having thesprings 7a arranged as shown, to hold the said rods up in front of rods1, but admit of its being readily pushed down out of the way whileshifting said rods. For securing the shores to the side of the platformof the car I provide them with a foot-piece, P, with a hole to receive avertical bolt, Q, with a nut and washer above it, the said bolt having ahook-head, R, and being placed in a metal case, S, open at the frontsides, as shown in' Fig. 5, and capable of being introduced in the metalstake-holdin g socket T of the car, the said case being provided with aspring, U, which throws the hook-headed bolt outward as soon as itpasses below the lower edge of the front wall V of the socket to engageit, so that the footpiece may be screwed down firmly upon the top of thecar-platform. These front pieces may also be secured to the overhangingedges of the platform by having the hook-headed bolts adjusted so thatthe heads engage the under side of the projecting bottom. The saidshores W are to be detachably connected to the top of the post A by apin, X, so as to be readily detached when required; but to save thelabor of making more than one connection thereat, (two shores beingnecessary,) we propose to pivot the two shores to a curved plate, Y,adapted to be connected to the post A by the pin X, as clearly shown,the said curved plate and the connection of the shores thereto being sothat the said shores may be folded together side by side, when notconnected to the post, to facilitate the handling and storing'of them.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent- 1. The combination of the keeper or guide Lwith the chain and chain-wheel, substantially as specified.

2. The arrangement, with the pawls G and pawl-levers F, of the rods a,springs e, and adjustable plate f, substantially as specified.

3. The foot-piece P, hook-headed bolt Q, case S, and spring T, combinedwith the shore and socketed stake-holder of a car, all substantially asspecified.

4. The combination, with levers K and rods I, of the rod i and springs70, substantially as specified.

WILLIAM M. HOWLAND. GEORGE L. HOWLAND. Witnesses:

JAMES BARRON,

CHARLES W. WILSON. (63)

